Brutally yank out multicore

30 files changed, 707 insertions, 742 deletions

diff --git a/Cargo.toml b/Cargo.toml
index d9561139..f7567a10 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -77,8 +77,6 @@ version = "0.5.2"
 trybuild = "1"
 
 [features]
-heterogeneous = ["cortex-m-rtic-macros/heterogeneous", "microamp"]
-homogeneous = ["cortex-m-rtic-macros/homogeneous"]
 # used for testing this crate; do not use in applications
 __v7 =[]
 __min_r1_43 =[]
@@ -89,8 +87,6 @@ lto = true
 
 [workspace]
 members = [
-  "heterogeneous",
-  "homogeneous",
   "macros",
 ]
 
diff --git a/macros/Cargo.toml b/macros/Cargo.toml
index 0a38d08b..e1dbce99 100644
--- a/macros/Cargo.toml
+++ b/macros/Cargo.toml
@@ -21,8 +21,5 @@ proc-macro = true
 proc-macro2 = "1"
 quote = "1"
 syn = "1"
-rtic-syntax = "0.4.0"
+rtic-syntax = { git = "https://github.com/AfoHT/rtic-syntax", branch = "multiremove", version = "0.4.0" }
 
-[features]
-heterogeneous = []
-homogeneous = []
diff --git a/macros/src/analyze.rs b/macros/src/analyze.rs
index af6811fa..c81c186d 100644
--- a/macros/src/analyze.rs
+++ b/macros/src/analyze.rs
@@ -4,14 +4,14 @@ use std::collections::{BTreeMap, BTreeSet};
 use rtic_syntax::{
     analyze::{self, Priority},
     ast::App,
-    Core, P,
+    P,
 };
 use syn::Ident;
 
 /// Extend the upstream `Analysis` struct with our field
 pub struct Analysis {
     parent: P<analyze::Analysis>,
-    pub interrupts: BTreeMap<Core, BTreeMap<Priority, Ident>>,
+    pub interrupts: BTreeMap<Priority, Ident>,
 }
 
 impl ops::Deref for Analysis {
@@ -25,32 +25,24 @@ impl ops::Deref for Analysis {
 // Assign an `extern` interrupt to each priority level
 pub fn app(analysis: P<analyze::Analysis>, app: &App) -> P<Analysis> {
     let mut interrupts = BTreeMap::new();
-    for core in 0..app.args.cores {
         let priorities = app
             .software_tasks
             .values()
             .filter_map(|task| {
-                if task.args.core == core {
                     Some(task.args.priority)
-                } else {
-                    None
-                }
             })
-            .chain(analysis.timer_queues.get(&core).map(|tq| tq.priority))
+            .chain(analysis.timer_queues.first().map(|tq| tq.priority))
             .collect::<BTreeSet<_>>();
 
         if !priorities.is_empty() {
-            interrupts.insert(
-                core,
+            interrupts =
                 priorities
                     .iter()
                     .cloned()
                     .rev()
-                    .zip(app.extern_interrupts[&core].keys().cloned())
-                    .collect(),
-            );
+                    .zip(app.extern_interrupts.keys().cloned())
+                    .collect();
         }
-    }
 
     P::new(Analysis {
         parent: analysis,
diff --git a/macros/src/check.rs b/macros/src/check.rs
index 71634446..0bc475e5 100644
--- a/macros/src/check.rs
+++ b/macros/src/check.rs
@@ -4,13 +4,14 @@ use proc_macro2::Span;
 use rtic_syntax::{
     analyze::Analysis,
     ast::{App, CustomArg},
+
 };
 use syn::{parse, Path};
 
 pub struct Extra<'a> {
     pub device: &'a Path,
     pub monotonic: Option<&'a Path>,
-    pub peripherals: Option<u8>,
+    pub peripherals: bool,
 }
 
 impl<'a> Extra<'a> {
@@ -20,35 +21,14 @@ impl<'a> Extra<'a> {
 }
 
 pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
-    if cfg!(feature = "homogeneous") {
-        // this RTIC mode uses the same namespace for all cores so we need to check that the
-        // identifiers used for each core `#[init]` and `#[idle]` functions don't collide
-        let mut seen = HashSet::new();
-
-        for name in app
-            .inits
-            .values()
-            .map(|init| &init.name)
-            .chain(app.idles.values().map(|idle| &idle.name))
-        {
-            if seen.contains(name) {
-                return Err(parse::Error::new(
-                    name.span(),
-                    "this identifier is already being used by another core",
-                ));
-            } else {
-                seen.insert(name);
-            }
-        }
-    }
-
     // check that all exceptions are valid; only exceptions with configurable priorities are
     // accepted
     for (name, task) in &app.hardware_tasks {
         let name_s = task.args.binds.to_string();
         match &*name_s {
             "SysTick" => {
-                if analysis.timer_queues.get(&task.args.core).is_some() {
+                // If the timer queue is used, then SysTick is unavailable
+                if !analysis.timer_queues.is_empty() {
                     return Err(parse::Error::new(
                         name.span(),
                         "this exception can't be used because it's being used by the runtime",
@@ -72,9 +52,7 @@ pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
     // check that external (device-specific) interrupts are not named after known (Cortex-M)
     // exceptions
     for name in app
-        .extern_interrupts
-        .iter()
-        .flat_map(|(_, interrupts)| interrupts.keys())
+        .extern_interrupts.keys()
     {
         let name_s = name.to_string();
 
@@ -93,50 +71,38 @@ pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
 
     // check that there are enough external interrupts to dispatch the software tasks and the timer
     // queue handler
-    for core in 0..app.args.cores {
-        let mut first = None;
-        let priorities = app
-            .software_tasks
-            .iter()
-            .filter_map(|(name, task)| {
-                if task.args.core == core {
-                    first = Some(name);
-                    Some(task.args.priority)
-                } else {
-                    None
-                }
-            })
-            .chain(analysis.timer_queues.get(&core).map(|tq| tq.priority))
-            .collect::<HashSet<_>>();
-
-        let need = priorities.len();
-        let given = app
-            .extern_interrupts
-            .get(&core)
-            .map(|ei| ei.len())
-            .unwrap_or(0);
-        if need > given {
-            let s = if app.args.cores == 1 {
-                format!(
-                    "not enough `extern` interrupts to dispatch \
-                     all software tasks (need: {}; given: {})",
-                    need, given
-                )
-            } else {
-                format!(
-                    "not enough `extern` interrupts to dispatch \
-                     all software tasks on this core (need: {}; given: {})",
-                    need, given
-                )
-            };
-
-            return Err(parse::Error::new(first.unwrap().span(), &s));
-        }
+    let mut first = None;
+    let priorities = app
+        .software_tasks
+        .iter()
+        .filter_map(|(name, task)| {
+            first = Some(name);
+            Some(task.args.priority)
+        })
+        .chain(analysis.timer_queues.first().map(|tq| tq.priority))
+        .collect::<HashSet<_>>();
+
+    let need = priorities.len();
+    let given = app
+        .extern_interrupts.len();
+    if need > given {
+        let s = {
+            format!(
+                "not enough `extern` interrupts to dispatch \
+                    all software tasks (need: {}; given: {})",
+                need, given
+            )
+        };
+
+        // If not enough tasks and first still is None, may cause
+        // "custom attribute panicked"
+        // unwrap on None
+        return Err(parse::Error::new(first.unwrap().span(), &s));
     }
 
     let mut device = None;
     let mut monotonic = None;
-    let mut peripherals = None;
+    let mut peripherals = false;
 
     for (k, v) in &app.args.custom {
         let ks = k.to_string();
@@ -165,10 +131,11 @@ pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
             },
 
             "peripherals" => match v {
-                CustomArg::Bool(x) if app.args.cores == 1 => {
-                    peripherals = if *x { Some(0) } else { None }
+                CustomArg::Bool(x) => {
+                    peripherals = if *x { true } else { false }
                 }
 
+                /*
                 CustomArg::UInt(s) if app.args.cores != 1 => {
                     let x = s.parse::<u8>().ok();
                     peripherals = if x.is_some() && x.unwrap() < app.args.cores {
@@ -184,15 +151,18 @@ pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
                         ));
                     }
                 }
+                */
 
                 _ => {
                     return Err(parse::Error::new(
                         k.span(),
-                        if app.args.cores == 1 {
-                            "unexpected argument value; this should be a boolean"
+                        //if app.args.cores == 1 {
+                            "unexpected argument value; this should be a boolean",
+                            /*
                         } else {
                             "unexpected argument value; this should be an integer"
                         },
+                            */
                     ));
                 }
             },
@@ -203,7 +173,7 @@ pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
         }
     }
 
-    if !analysis.timer_queues.is_empty() && monotonic.is_none() {
+    if !&analysis.timer_queues.is_empty() && monotonic.is_none() {
         return Err(parse::Error::new(
             Span::call_site(),
             "a `monotonic` timer must be specified to use the `schedule` API",
diff --git a/macros/src/codegen-verbose.rs b/macros/src/codegen-verbose.rs
new file mode 100644
index 00000000..2b71cf5c
--- /dev/null
+++ b/macros/src/codegen-verbose.rs
@@ -0,0 +1,226 @@
+use proc_macro2::TokenStream as TokenStream2;
+use quote::quote;
+use rtic_syntax::ast::App;
+
+use crate::{analyze::Analysis, check::Extra};
+
+mod assertions;
+mod dispatchers;
+mod hardware_tasks;
+mod idle;
+mod init;
+mod locals;
+mod module;
+mod post_init;
+mod pre_init;
+mod resources;
+mod resources_struct;
+mod schedule;
+mod schedule_body;
+mod software_tasks;
+mod spawn;
+mod spawn_body;
+mod timer_queue;
+mod util;
+
+// TODO document the syntax here or in `rtic-syntax`
+pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
+    let mut const_app = vec![];
+    let mut mains = vec![];
+    let mut root = vec![];
+    let mut user = vec![];
+    let mut imports = vec![];
+
+    // generate a `main` function for each core
+    for core in 0..app.args.cores {
+        let assertion_stmts = assertions::codegen(core, analysis, extra);
+
+        let (const_app_pre_init, pre_init_stmts) = pre_init::codegen(core, &app, analysis, extra);
+
+        let (const_app_init, _root_init, user_init, user_init_imports, call_init) =
+            init::codegen(core, app, analysis, extra);
+
+        let (const_app_post_init, post_init_stmts) =
+            post_init::codegen(core, &app, analysis, extra);
+
+        let (const_app_idle, _root_idle, user_idle, user_idle_imports, call_idle) =
+            idle::codegen(core, app, analysis, extra);
+
+        user.push(quote!(
+            /// USER INIT
+            #user_init
+
+            /// USER IDLE
+            #user_idle
+        ));
+
+        // Stow away the imports generated for each core
+        imports.push(quote!(
+            /// USER IMPORTS
+            #(#user_init_imports)*
+
+            /// USER IDLE
+            #(#user_idle_imports)*
+        ));
+
+        root.push(quote!(
+            #(#_root_init)*
+
+            #(#_root_idle)*
+        ));
+
+        const_app.push(quote!(
+            #(#const_app_pre_init)*
+
+            #const_app_init
+
+            #(#const_app_post_init)*
+
+            #const_app_idle
+        ));
+
+        let cfg_core = util::cfg_core(core, app.args.cores);
+        let main = util::suffixed("main", core);
+        let section = util::link_section("text", core);
+        mains.push(quote!(
+            #[no_mangle]
+            #section
+            #cfg_core
+            unsafe extern "C" fn #main() -> ! {
+                #(#assertion_stmts)*
+
+                #(#pre_init_stmts)*
+
+                #call_init
+
+                #(#post_init_stmts)*
+
+                #call_idle
+            }
+        ));
+    }
+
+    let (const_app_resources, mod_resources, mod_resources_imports) =
+        resources::codegen(app, analysis, extra);
+
+    let (
+        const_app_hardware_tasks,
+        root_hardware_tasks,
+        user_hardware_tasks,
+        user_hardware_tasks_imports,
+    ) = hardware_tasks::codegen(app, analysis, extra);
+
+    let (
+        const_app_software_tasks,
+        root_software_tasks,
+        user_software_tasks,
+        user_software_tasks_imports,
+    ) = software_tasks::codegen(app, analysis, extra);
+
+    let const_app_dispatchers = dispatchers::codegen(app, analysis, extra);
+
+    let const_app_spawn = spawn::codegen(app, analysis, extra);
+
+    let const_app_timer_queue = timer_queue::codegen(app, analysis, extra);
+
+    let const_app_schedule = schedule::codegen(app, extra);
+
+    let cores = app.args.cores.to_string();
+    let cfg_core = quote!(#[cfg(core = #cores)]);
+    let msg = format!(
+        "specified {} core{} but tried to compile for more than {0} core{1}",
+        app.args.cores,
+        if app.args.cores > 1 { "s" } else { "" }
+    );
+    let check_excess_cores = quote!(
+        #cfg_core
+        compile_error!(#msg);
+    );
+
+    /*
+    for s in root.clone() {
+        println!("{}", s.to_string());
+    }
+    */
+
+    let user_imports = app.user_imports.clone();
+    let user_code = app.user_code.clone();
+    let name = &app.name;
+    let device = extra.device;
+    let endresult = quote!(
+        /// USER
+        #(#user)*
+
+        /// USER_HW_TASKS
+        #(#user_hardware_tasks)*
+
+        /// USER_SW_TASKS
+        #(#user_software_tasks)*
+
+        /// ROOT
+        //#(#root)*
+
+        /// MOD_RESOURCES
+        #mod_resources
+
+        /// root_hardware_tasks
+        #(#root_hardware_tasks)*
+
+        /// root_software_tasks
+        #(#root_software_tasks)*
+
+        /// Implementation details
+        mod #name {
+            /// Always include the device crate which contains the vector table
+            use #device as _;
+            #(#imports)*
+            /// User imports
+            #(#user_imports)*
+
+            /// User code from within the module
+            #(#user_code)*
+
+            /// User hardware tasks import
+            #(#user_hardware_tasks_imports)*
+
+            /// User software_tasks
+            #(#user_software_tasks_imports)*
+
+            /// Mod resources imports
+            #(#mod_resources_imports)*
+
+            #check_excess_cores
+
+            /// Const app
+            #(#const_app)*
+
+            /// Const app resources
+            #(#const_app_resources)*
+
+            /// Const app hw tasks
+            #(#const_app_hardware_tasks)*
+
+            /// Const app sw tasks
+            #(#const_app_software_tasks)*
+
+            /// Const app dispatchers
+            #(#const_app_dispatchers)*
+
+            /// Const app spawn
+            #(#const_app_spawn)*
+            /// Const app spawn end
+
+            #(#const_app_timer_queue)*
+
+            #(#const_app_schedule)*
+
+            /// Mains
+            #(#mains)*
+        }
+    );
+    for s in endresult.clone() {
+        eprintln!("{}", s.to_string());
+    }
+
+    endresult
+}
diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index 2433684c..73531c9b 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -30,65 +30,60 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
     let mut root = vec![];
     let mut user = vec![];
 
-    // generate a `main` function for each core
-    for core in 0..app.args.cores {
-        let assertion_stmts = assertions::codegen(core, analysis, extra);
+    // generate the `main` function
+    let assertion_stmts = assertions::codegen(analysis);
 
-        let (const_app_pre_init, pre_init_stmts) = pre_init::codegen(core, &app, analysis, extra);
+    let pre_init_stmts = pre_init::codegen(&app, analysis, extra);
 
-        let (const_app_init, root_init, user_init, call_init) =
-            init::codegen(core, app, analysis, extra);
+    let (const_app_init, root_init, user_init, call_init) =
+        init::codegen(app, analysis, extra);
 
-        let (const_app_post_init, post_init_stmts) =
-            post_init::codegen(core, &app, analysis, extra);
+    let (const_app_post_init, post_init_stmts) =
+        post_init::codegen(&app, analysis);
 
-        let (const_app_idle, root_idle, user_idle, call_idle) =
-            idle::codegen(core, app, analysis, extra);
+    let (const_app_idle, root_idle, user_idle, call_idle) =
+        idle::codegen(app, analysis, extra);
 
-        user.push(quote!(
-            #user_init
+    user.push(quote!(
+        #user_init
 
-            #user_idle
-        ));
+        #user_idle
+    ));
 
-        root.push(quote!(
-            #(#root_init)*
+    root.push(quote!(
+        #(#root_init)*
 
-            #(#root_idle)*
-        ));
+        #(#root_idle)*
+    ));
 
-        const_app.push(quote!(
-            #(#const_app_pre_init)*
+    const_app.push(quote!(
+        #const_app_init
 
-            #const_app_init
+        #(#const_app_post_init)*
 
-            #(#const_app_post_init)*
+        #const_app_idle
+    ));
 
-            #const_app_idle
-        ));
+    let main = util::suffixed("main");
+    let section = util::link_section("text");
+    mains.push(quote!(
+        #[no_mangle]
+        #section
+        unsafe extern "C" fn #main() -> ! {
+            let _TODO: () = ();
 
-        let cfg_core = util::cfg_core(core, app.args.cores);
-        let main = util::suffixed("main", core);
-        let section = util::link_section("text", core);
-        mains.push(quote!(
-            #[no_mangle]
-            #section
-            #cfg_core
-            unsafe extern "C" fn #main() -> ! {
-                let _TODO: () = ();
+            #(#assertion_stmts)*
 
-                #(#assertion_stmts)*
+            #(#pre_init_stmts)*
 
-                #(#pre_init_stmts)*
+            #call_init
 
-                #call_init
+            #(#post_init_stmts)*
 
-                #(#post_init_stmts)*
+            #call_idle
+        }
+    ));
 
-                #call_idle
-            }
-        ));
-    }
 
     let (const_app_resources, mod_resources) = resources::codegen(app, analysis, extra);
 
@@ -106,18 +101,6 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
 
     let const_app_schedule = schedule::codegen(app, extra);
 
-    let cores = app.args.cores.to_string();
-    let cfg_core = quote!(#[cfg(core = #cores)]);
-    let msg = format!(
-        "specified {} core{} but tried to compile for more than {0} core{1}",
-        app.args.cores,
-        if app.args.cores > 1 { "s" } else { "" }
-    );
-    let check_excess_cores = quote!(
-        #cfg_core
-        compile_error!(#msg);
-    );
-
     let name = &app.name;
     let device = extra.device;
     quote!(
@@ -141,8 +124,6 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
             /// Always include the device crate which contains the vector table
             use #device as _;
 
-            #check_excess_cores
-
             #(#const_app)*
 
             #(#const_app_resources)*
diff --git a/macros/src/codegen/assertions.rs b/macros/src/codegen/assertions.rs
index 51bbdbff..a7c26a5e 100644
--- a/macros/src/codegen/assertions.rs
+++ b/macros/src/codegen/assertions.rs
@@ -1,33 +1,35 @@
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 
-use crate::{analyze::Analysis, check::Extra};
+use crate::analyze::Analysis;
 
 /// Generates compile-time assertions that check that types implement the `Send` / `Sync` traits
-pub fn codegen(core: u8, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream2> {
+pub fn codegen(analysis: &Analysis) -> Vec<TokenStream2> {
     let mut stmts = vec![];
 
     // we don't generate *all* assertions on all cores because the user could conditionally import a
     // type only on some core (e.g. `#[cfg(core = "0")] use some::Type;`)
 
-    if let Some(types) = analysis.send_types.get(&core) {
-        for ty in types {
+    //if let Some(types) = analysis.send_types {
+        for ty in &analysis.send_types {
             stmts.push(quote!(rtic::export::assert_send::<#ty>();));
         }
-    }
+    //}
 
-    if let Some(types) = analysis.sync_types.get(&core) {
-        for ty in types {
+    //if let Some(types) = analysis.sync_types {
+        for ty in &analysis.sync_types {
             stmts.push(quote!(rtic::export::assert_sync::<#ty>();));
         }
-    }
+    //}
 
     // if the `schedule` API is used in more than one core then we need to check that the
     // `monotonic` timer can be used in multi-core context
+    /*
     if analysis.timer_queues.len() > 1 && analysis.timer_queues.contains_key(&core) {
         let monotonic = extra.monotonic();
         stmts.push(quote!(rtic::export::assert_multicore::<#monotonic>();));
     }
+    */
 
     stmts
 }
diff --git a/macros/src/codegen/dispatchers.rs b/macros/src/codegen/dispatchers.rs
index 60b8626e..fdeb6155 100644
--- a/macros/src/codegen/dispatchers.rs
+++ b/macros/src/codegen/dispatchers.rs
@@ -8,181 +8,151 @@ use crate::{analyze::Analysis, check::Extra, codegen::util};
 pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream2> {
     let mut items = vec![];
 
-    for (&receiver, dispatchers) in &analysis.channels {
-        let interrupts = &analysis.interrupts[&receiver];
+    let interrupts = &analysis.interrupts;
+
+    for (&level, channel) in &analysis.channels {
+        let mut stmts = vec![];
+
+        let variants = channel
+            .tasks
+            .iter()
+            .map(|name| {
+                let cfgs = &app.software_tasks[name].cfgs;
+
+                quote!(
+                    #(#cfgs)*
+                    #name
+                )
+            })
+            .collect::<Vec<_>>();
+
+        let doc = format!(
+            "Software tasks to be dispatched at priority level {}",
+            level,
+        );
+        let t = util::spawn_t_ident(level);
+        items.push(quote!(
+            #[allow(non_camel_case_types)]
+            #[derive(Clone, Copy)]
+            #[doc = #doc]
+            enum #t {
+                #(#variants,)*
+            }
+        ));
+
+        let n = util::capacity_typenum(channel.capacity, true);
+        let rq = util::rq_ident(level);
+        let (rq_ty, rq_expr, section) = {
+            (
+                quote!(rtic::export::SCRQ<#t, #n>),
+                quote!(rtic::export::Queue(unsafe {
+                    rtic::export::iQueue::u8_sc()
+                })),
+                util::link_section("bss"),
+            )
+        };
+
+        let doc = format!(
+            "Queue of tasks ready to be dispatched at priority level {}",
+            level
+        );
+        items.push(quote!(
+            #[doc = #doc]
+            #section
+            static mut #rq: #rq_ty = #rq_expr;
+        ));
+
+        if let Some(ceiling) = channel.ceiling {
+            items.push(quote!(
+                struct #rq<'a> {
+                    priority: &'a rtic::export::Priority,
+                }
+            ));
 
-        for (&level, channels) in dispatchers {
-            let mut stmts = vec![];
+            items.push(util::impl_mutex(
+                extra,
+                &[],
+                false,
+                &rq,
+                rq_ty,
+                ceiling,
+                quote!(&mut #rq),
+            ));
+        }
 
-            for (&sender, channel) in channels {
-                let cfg_sender = util::cfg_core(sender, app.args.cores);
+        let arms = channel
+            .tasks
+            .iter()
+            .map(|name| {
+                let task = &app.software_tasks[name];
+                let cfgs = &task.cfgs;
+                let fq = util::fq_ident(name);
+                let inputs = util::inputs_ident(name);
+                let (_, tupled, pats, _) = util::regroup_inputs(&task.inputs);
 
-                let variants = channel
-                    .tasks
-                    .iter()
-                    .map(|name| {
-                        let cfgs = &app.software_tasks[name].cfgs;
+                let (let_instant, instant) = if app.uses_schedule() {
+                    let instants = util::instants_ident(name);
 
-                        quote!(
-                            #(#cfgs)*
-                            #name
-                        )
-                    })
-                    .collect::<Vec<_>>();
-
-                let doc = format!(
-                    "Software tasks spawned from core #{} to be dispatched at priority level {} by core #{}",
-                    sender, level, receiver,
-                );
-                let t = util::spawn_t_ident(receiver, level, sender);
-                items.push(quote!(
-                    #[allow(non_camel_case_types)]
-                    #[derive(Clone, Copy)]
-                    #[doc = #doc]
-                    enum #t {
-                        #(#variants,)*
-                    }
-                ));
-
-                let n = util::capacity_typenum(channel.capacity, true);
-                let rq = util::rq_ident(receiver, level, sender);
-                let (rq_attr, rq_ty, rq_expr, section) = if sender == receiver {
                     (
-                        cfg_sender.clone(),
-                        quote!(rtic::export::SCRQ<#t, #n>),
-                        quote!(rtic::export::Queue(unsafe {
-                            rtic::export::iQueue::u8_sc()
-                        })),
-                        util::link_section("bss", sender),
+                        quote!(
+                            let instant =
+                                #instants.get_unchecked(usize::from(index)).as_ptr().read();
+                        ),
+                        quote!(, instant),
                     )
                 } else {
-                    let shared = if cfg!(feature = "heterogeneous") {
-                        Some(quote!(#[rtic::export::shared]))
-                    } else {
-                        None
-                    };
-
-                    (
-                        shared,
-                        quote!(rtic::export::MCRQ<#t, #n>),
-                        quote!(rtic::export::Queue(rtic::export::iQueue::u8())),
-                        None,
-                    )
+                    (quote!(), quote!())
                 };
 
-                let doc = format!(
-                    "Queue of tasks sent by core #{} ready to be dispatched by core #{} at priority level {}",
-                    sender,
-                    receiver,
-                    level
-                );
-                items.push(quote!(
-                    #[doc = #doc]
-                    #rq_attr
-                    #section
-                    static mut #rq: #rq_ty = #rq_expr;
-                ));
-
-                if let Some(ceiling) = channel.ceiling {
-                    items.push(quote!(
-                        #cfg_sender
-                        struct #rq<'a> {
-                            priority: &'a rtic::export::Priority,
-                        }
-                    ));
-
-                    items.push(util::impl_mutex(
-                        extra,
-                        &[],
-                        cfg_sender.as_ref(),
-                        false,
-                        &rq,
-                        rq_ty,
-                        ceiling,
-                        quote!(&mut #rq),
-                    ));
-                }
-
-                let arms = channel
-                    .tasks
-                    .iter()
-                    .map(|name| {
-                        let task = &app.software_tasks[name];
-                        let cfgs = &task.cfgs;
-                        let fq = util::fq_ident(name, sender);
-                        let inputs = util::inputs_ident(name, sender);
-                        let (_, tupled, pats, _) = util::regroup_inputs(&task.inputs);
-
-                        let (let_instant, instant) = if app.uses_schedule(receiver) {
-                            let instants = util::instants_ident(name, sender);
-
-                            (
-                                quote!(
-                                    let instant =
-                                        #instants.get_unchecked(usize::from(index)).as_ptr().read();
-                                ),
-                                quote!(, instant),
-                            )
-                        } else {
-                            (quote!(), quote!())
-                        };
-
-                        let locals_new = if task.locals.is_empty() {
-                            quote!()
-                        } else {
-                            quote!(#name::Locals::new(),)
-                        };
+                let locals_new = if task.locals.is_empty() {
+                    quote!()
+                } else {
+                    quote!(#name::Locals::new(),)
+                };
 
-                        quote!(
-                            #(#cfgs)*
-                            #t::#name => {
-                                let #tupled =
-                                    #inputs.get_unchecked(usize::from(index)).as_ptr().read();
-                                #let_instant
-                                #fq.split().0.enqueue_unchecked(index);
-                                let priority = &rtic::export::Priority::new(PRIORITY);
-                                crate::#name(
-                                    #locals_new
-                                    #name::Context::new(priority #instant)
-                                    #(,#pats)*
-                                )
-                            }
+                quote!(
+                    #(#cfgs)*
+                    #t::#name => {
+                        let #tupled =
+                            #inputs.get_unchecked(usize::from(index)).as_ptr().read();
+                        #let_instant
+                        #fq.split().0.enqueue_unchecked(index);
+                        let priority = &rtic::export::Priority::new(PRIORITY);
+                        crate::#name(
+                            #locals_new
+                            #name::Context::new(priority #instant)
+                            #(,#pats)*
                         )
-                    })
-                    .collect::<Vec<_>>();
-
-                stmts.push(quote!(
-                    while let Some((task, index)) = #rq.split().1.dequeue() {
-                        match task {
-                            #(#arms)*
-                        }
                     }
-                ));
-            }
-
-            let doc = format!(
-                "Interrupt handler used by core #{} to dispatch tasks at priority {}",
-                receiver, level
-            );
-            let cfg_receiver = util::cfg_core(receiver, app.args.cores);
-            let section = util::link_section("text", receiver);
-            let interrupt = util::suffixed(&interrupts[&level].to_string(), receiver);
-            items.push(quote!(
-                #[allow(non_snake_case)]
-                #[doc = #doc]
-                #[no_mangle]
-                #cfg_receiver
-                #section
-                unsafe fn #interrupt() {
-                    /// The priority of this interrupt handler
-                    const PRIORITY: u8 = #level;
-
-                    rtic::export::run(PRIORITY, || {
-                        #(#stmts)*
-                    });
+                )
+            })
+            .collect::<Vec<_>>();
+
+        stmts.push(quote!(
+            while let Some((task, index)) = #rq.split().1.dequeue() {
+                match task {
+                    #(#arms)*
                 }
-            ));
-        }
+            }
+        ));
+
+        let doc = format!("Interrupt handler to dispatch tasks at priority {}", level);
+        let section = util::link_section("text");
+        let interrupt = util::suffixed(&interrupts[&level].to_string());
+        items.push(quote!(
+            #[allow(non_snake_case)]
+            #[doc = #doc]
+            #[no_mangle]
+            #section
+            unsafe fn #interrupt() {
+                /// The priority of this interrupt handler
+                const PRIORITY: u8 = #level;
+
+                rtic::export::run(PRIORITY, || {
+                    #(#stmts)*
+                });
+            }
+        ));
     }
 
     items
diff --git a/macros/src/codegen/hardware_tasks.rs b/macros/src/codegen/hardware_tasks.rs
index 453dbccb..37df33de 100644
--- a/macros/src/codegen/hardware_tasks.rs
+++ b/macros/src/codegen/hardware_tasks.rs
@@ -29,10 +29,8 @@ pub fn codegen(
     let mut user_tasks = vec![];
 
     for (name, task) in &app.hardware_tasks {
-        let core = task.args.core;
-        let cfg_core = util::cfg_core(core, app.args.cores);
 
-        let (let_instant, instant) = if app.uses_schedule(core) {
+        let (let_instant, instant) = if app.uses_schedule() {
             let m = extra.monotonic();
 
             (
@@ -49,19 +47,14 @@ pub fn codegen(
             quote!(#name::Locals::new(),)
         };
 
-        let symbol = if cfg!(feature = "homogeneous") {
-            util::suffixed(&task.args.binds.to_string(), core)
-        } else {
-            task.args.binds.clone()
-        };
+        let symbol = task.args.binds.clone();
         let priority = task.args.priority;
 
-        let section = util::link_section("text", core);
+        let section = util::link_section("text");
         const_app.push(quote!(
             #[allow(non_snake_case)]
             #[no_mangle]
             #section
-            #cfg_core
             unsafe fn #symbol() {
                 const PRIORITY: u8 = #priority;
 
@@ -104,7 +97,7 @@ pub fn codegen(
         let mut locals_pat = None;
         if !task.locals.is_empty() {
             let (struct_, pat) =
-                locals::codegen(Context::HardwareTask(name), &task.locals, core, app);
+                locals::codegen(Context::HardwareTask(name), &task.locals, app);
 
             root.push(struct_);
             locals_pat = Some(pat);
@@ -113,8 +106,7 @@ pub fn codegen(
         let attrs = &task.attrs;
         let context = &task.context;
         let stmts = &task.stmts;
-        let section = util::link_section("text", core);
-        // XXX shouldn't this have a cfg_core?
+        let section = util::link_section("text");
         let locals_pat = locals_pat.iter();
         user_tasks.push(quote!(
             #(#attrs)*
diff --git a/macros/src/codegen/idle.rs b/macros/src/codegen/idle.rs
index 032c8ade..853372db 100644
--- a/macros/src/codegen/idle.rs
+++ b/macros/src/codegen/idle.rs
@@ -10,7 +10,6 @@ use crate::{
 
 /// Generates support code for `#[idle]` functions
 pub fn codegen(
-    core: u8,
     app: &App,
     analysis: &Analysis,
     extra: &Extra,
@@ -27,7 +26,9 @@ pub fn codegen(
     // call_idle
     TokenStream2,
 ) {
-    if let Some(idle) = app.idles.get(&core) {
+    //if let Some(idle) = app.idles.get(&core) {
+    if app.idles.len() > 0 {
+        let idle = &app.idles[0];
         let mut needs_lt = false;
         let mut const_app = None;
         let mut root_idle = vec![];
@@ -36,7 +37,7 @@ pub fn codegen(
 
         if !idle.args.resources.is_empty() {
             let (item, constructor) =
-                resources_struct::codegen(Context::Idle(core), 0, &mut needs_lt, app, analysis);
+                resources_struct::codegen(Context::Idle, 0, &mut needs_lt, app, analysis);
 
             root_idle.push(item);
             const_app = Some(constructor);
@@ -44,25 +45,23 @@ pub fn codegen(
 
         let name = &idle.name;
         if !idle.locals.is_empty() {
-            let (locals, pat) = locals::codegen(Context::Idle(core), &idle.locals, core, app);
+            let (locals, pat) = locals::codegen(Context::Idle, &idle.locals, app);
 
             locals_new = Some(quote!(#name::Locals::new()));
             locals_pat = Some(pat);
             root_idle.push(locals);
         }
 
-        root_idle.push(module::codegen(Context::Idle(core), needs_lt, app, extra));
+        root_idle.push(module::codegen(Context::Idle, needs_lt, app, extra));
 
-        let cfg_core = util::cfg_core(core, app.args.cores);
         let attrs = &idle.attrs;
         let context = &idle.context;
         let stmts = &idle.stmts;
-        let section = util::link_section("text", core);
+        let section = util::link_section("text");
         let locals_pat = locals_pat.iter();
         let user_idle = Some(quote!(
             #(#attrs)*
             #[allow(non_snake_case)]
-            #cfg_core
             #section
             fn #name(#(#locals_pat,)* #context: #name::Context) -> ! {
                 use rtic::Mutex as _;
diff --git a/macros/src/codegen/init.rs b/macros/src/codegen/init.rs
index fa273fee..4ae9fa62 100644
--- a/macros/src/codegen/init.rs
+++ b/macros/src/codegen/init.rs
@@ -10,7 +10,6 @@ use crate::{
 
 /// Generates support code for `#[init]` functions
 pub fn codegen(
-    core: u8,
     app: &App,
     analysis: &Analysis,
     extra: &Extra,
@@ -28,8 +27,9 @@ pub fn codegen(
     // call_init -- the call to the user `#[init]` if there's one
     Option<TokenStream2>,
 ) {
-    if let Some(init) = app.inits.get(&core) {
-        let cfg_core = util::cfg_core(core, app.args.cores);
+    //if let Some(init) = app.inits.get(&core) {
+    if app.inits.len() > 0 {
+        let init = &app.inits[0];
         let mut needs_lt = false;
         let name = &init.name;
 
@@ -38,8 +38,8 @@ pub fn codegen(
         let ret = {
             let late_fields = analysis
                 .late_resources
-                .get(&core)
-                .map(|resources| {
+                .iter()
+                .flat_map(|resources| {
                     resources
                         .iter()
                         .map(|name| {
@@ -51,16 +51,14 @@ pub fn codegen(
                             pub #name: #ty
                             )
                         })
-                        .collect::<Vec<_>>()
                 })
-                .unwrap_or(vec![]);
+                .collect::<Vec<_>>();
 
             if !late_fields.is_empty() {
                 let late_resources = util::late_resources_ident(&name);
 
                 root_init.push(quote!(
                     /// Resources initialized at runtime
-                    #cfg_core
                     #[allow(non_snake_case)]
                     pub struct #late_resources {
                         #(#late_fields),*
@@ -76,7 +74,7 @@ pub fn codegen(
         let mut locals_pat = None;
         let mut locals_new = None;
         if !init.locals.is_empty() {
-            let (struct_, pat) = locals::codegen(Context::Init(core), &init.locals, core, app);
+            let (struct_, pat) = locals::codegen(Context::Init, &init.locals, app);
 
             locals_new = Some(quote!(#name::Locals::new()));
             locals_pat = Some(pat);
@@ -86,11 +84,10 @@ pub fn codegen(
         let context = &init.context;
         let attrs = &init.attrs;
         let stmts = &init.stmts;
-        let section = util::link_section("text", core);
+        let section = util::link_section("text");
         let locals_pat = locals_pat.iter();
         let user_init = Some(quote!(
             #(#attrs)*
-            #cfg_core
             #[allow(non_snake_case)]
             #section
             fn #name(#(#locals_pat,)* #context: #name::Context) #ret {
@@ -101,7 +98,7 @@ pub fn codegen(
         let mut const_app = None;
         if !init.args.resources.is_empty() {
             let (item, constructor) =
-                resources_struct::codegen(Context::Init(core), 0, &mut needs_lt, app, analysis);
+                resources_struct::codegen(Context::Init, 0, &mut needs_lt, app, analysis);
 
             root_init.push(item);
             const_app = Some(constructor);
@@ -112,7 +109,7 @@ pub fn codegen(
             quote!(let late = crate::#name(#(#locals_new,)* #name::Context::new(core.into()));),
         );
 
-        root_init.push(module::codegen(Context::Init(core), needs_lt, app, extra));
+        root_init.push(module::codegen(Context::Init, needs_lt, app, extra));
 
         (const_app, root_init, user_init, call_init)
     } else {
diff --git a/macros/src/codegen/locals.rs b/macros/src/codegen/locals.rs
index 127f4b09..b3c593a2 100644
--- a/macros/src/codegen/locals.rs
+++ b/macros/src/codegen/locals.rs
@@ -2,7 +2,7 @@ use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 use rtic_syntax::{
     ast::{App, Local},
-    Context, Core, Map,
+    Context, Map,
 };
 
 use crate::codegen::util;
@@ -10,7 +10,6 @@ use crate::codegen::util;
 pub fn codegen(
     ctxt: Context,
     locals: &Map<Local>,
-    core: Core,
     app: &App,
 ) -> (
     // locals
@@ -42,11 +41,13 @@ pub fn codegen(
         let cfgs = &local.cfgs;
         has_cfgs |= !cfgs.is_empty();
 
+        /*
         let section = if local.shared && cfg!(feature = "heterogeneous") {
             Some(quote!(#[rtic::export::shared]))
         } else {
             util::link_section("data", core)
         };
+        */
         let expr = &local.expr;
         let ty = &local.ty;
         fields.push(quote!(
@@ -55,7 +56,7 @@ pub fn codegen(
         ));
         items.push(quote!(
             #(#cfgs)*
-            #section
+            //#section
             static mut #name: #ty = #expr
         ));
         values.push(quote!(
diff --git a/macros/src/codegen/module.rs b/macros/src/codegen/module.rs
index 1b21209f..ad20f139 100644
--- a/macros/src/codegen/module.rs
+++ b/macros/src/codegen/module.rs
@@ -11,12 +11,12 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
 
     let name = ctxt.ident(app);
 
-    let core = ctxt.core(app);
+    //let core = ctxt.core(app);
     let mut needs_instant = false;
     let mut lt = None;
     match ctxt {
-        Context::Init(core) => {
-            if app.uses_schedule(core) {
+        Context::Init => {
+            if app.uses_schedule() {
                 let m = extra.monotonic();
 
                 fields.push(quote!(
@@ -37,7 +37,7 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
                 ));
             }
 
-            if extra.peripherals == Some(core) {
+            if extra.peripherals {
                 let device = extra.device;
 
                 fields.push(quote!(
@@ -51,10 +51,10 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
             values.push(quote!(core));
         }
 
-        Context::Idle(..) => {}
+        Context::Idle => {}
 
         Context::HardwareTask(..) => {
-            if app.uses_schedule(core) {
+            if app.uses_schedule() {
                 let m = extra.monotonic();
 
                 fields.push(quote!(
@@ -69,7 +69,7 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
         }
 
         Context::SoftwareTask(..) => {
-            if app.uses_schedule(core) {
+            if app.uses_schedule() {
                 let m = extra.monotonic();
 
                 fields.push(quote!(
@@ -205,7 +205,7 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
 
                 values.push(quote!(spawn: Spawn { priority }));
             } else {
-                let instant_field = if app.uses_schedule(core) {
+                let instant_field = if app.uses_schedule() {
                     let m = extra.monotonic();
 
                     needs_instant = true;
@@ -252,8 +252,8 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
         }
     }
 
-    if let Context::Init(core) = ctxt {
-        let init = &app.inits[&core];
+    if let Context::Init = ctxt {
+        let init = &app.inits[0];
         if init.returns_late_resources {
             let late_resources = util::late_resources_ident(&init.name);
 
@@ -265,14 +265,14 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
     }
 
     let doc = match ctxt {
-        Context::Idle(_) => "Idle loop",
-        Context::Init(_) => "Initialization function",
+        Context::Idle => "Idle loop",
+        Context::Init => "Initialization function",
         Context::HardwareTask(_) => "Hardware task",
         Context::SoftwareTask(_) => "Software task",
     };
 
     let core = if ctxt.is_init() {
-        if app.uses_schedule(core) {
+        if app.uses_schedule() {
             Some(quote!(core: rtic::Peripherals,))
         } else {
             Some(quote!(core: rtic::export::Peripherals,))
@@ -312,12 +312,12 @@ pub fn codegen(ctxt: Context, resources_tick: bool, app: &App, extra: &Extra) ->
     ));
 
     if !items.is_empty() {
-        let cfg_core = util::cfg_core(ctxt.core(app), app.args.cores);
+        //let cfg_core = util::cfg_core(ctxt.core(app), app.args.cores);
 
         quote!(
             #[allow(non_snake_case)]
             #[doc = #doc]
-            #cfg_core
+            //#cfg_core
             pub mod #name {
                 #(#items)*
             }
diff --git a/macros/src/codegen/post_init.rs b/macros/src/codegen/post_init.rs
index 0c740e85..098d1cc9 100644
--- a/macros/src/codegen/post_init.rs
+++ b/macros/src/codegen/post_init.rs
@@ -2,21 +2,24 @@ use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 use rtic_syntax::ast::App;
 
-use crate::{analyze::Analysis, check::Extra, codegen::util};
+use crate::analyze::Analysis;
 
 /// Generates code that runs after `#[init]` returns
 pub fn codegen(
-    core: u8,
     app: &App,
     analysis: &Analysis,
-    extra: &Extra,
 ) -> (Vec<TokenStream2>, Vec<TokenStream2>) {
-    let mut const_app = vec![];
+    //#TODO remove
+    let const_app = vec![];
     let mut stmts = vec![];
 
     // initialize late resources
-    if let Some(late_resources) = analysis.late_resources.get(&core) {
-        for name in late_resources {
+    //if let Some(late_resources) = analysis.late_resources {
+        //for name in late_resources {
+    if analysis.late_resources.len() > 0 {
+        // #TODO, check soundness of this, why the wrapping
+        // BTreeSet wrapped in a vector
+        for name in &analysis.late_resources[0] {
             // if it's live
             let cfgs = app.late_resources[name].cfgs.clone();
             if analysis.locations.get(name).is_some() {
@@ -29,7 +32,9 @@ pub fn codegen(
         }
     }
 
+    /*
     if analysis.timer_queues.is_empty() {
+        /*
         // cross-initialization barriers -- notify *other* cores that their resources have been
         // initialized
         for (user, initializers) in &analysis.initialization_barriers {
@@ -55,7 +60,9 @@ pub fn codegen(
                 #ib.release();
             ));
         }
+        */
 
+        /*
         // then wait until the other cores have initialized *our* resources
         if analysis.initialization_barriers.contains_key(&core) {
             let ib = util::init_barrier(core);
@@ -75,6 +82,7 @@ pub fn codegen(
                 ));
             }
         }
+        */
     } else {
         // if the `schedule` API is used then we'll synchronize all cores to leave the
         // `init`-ialization phase at the same time. In this case the rendezvous barrier makes the
@@ -154,6 +162,7 @@ pub fn codegen(
             }
         }
     }
+    */
 
     // enable the interrupts -- this completes the `init`-ialization phase
     stmts.push(quote!(rtic::export::interrupt::enable();));
diff --git a/macros/src/codegen/pre_init.rs b/macros/src/codegen/pre_init.rs
index f89dec96..7b577390 100644
--- a/macros/src/codegen/pre_init.rs
+++ b/macros/src/codegen/pre_init.rs
@@ -6,60 +6,44 @@ use crate::{analyze::Analysis, check::Extra, codegen::util};
 
 /// Generates code that runs before `#[init]`
 pub fn codegen(
-    core: u8,
     app: &App,
     analysis: &Analysis,
     extra: &Extra,
-) -> (
-    // `const_app_pre_init` -- `static` variables for barriers
-    Vec<TokenStream2>,
+) ->
     // `pre_init_stmts`
-    Vec<TokenStream2>,
-) {
-    let mut const_app = vec![];
+    Vec<TokenStream2>
+{
     let mut stmts = vec![];
 
     // disable interrupts -- `init` must run with interrupts disabled
     stmts.push(quote!(rtic::export::interrupt::disable();));
 
-    // populate this core `FreeQueue`s
-    for (name, senders) in &analysis.free_queues {
+    // populate the FreeQueue
+    for fq in &analysis.free_queues {
+        // Get the task name
+        let name = fq.0;
         let task = &app.software_tasks[name];
         let cap = task.args.capacity;
 
-        for &sender in senders.keys() {
-            if sender == core {
-                let fq = util::fq_ident(name, sender);
+        let fq_ident = util::fq_ident(name);
 
-                stmts.push(quote!(
-                    (0..#cap).for_each(|i| #fq.enqueue_unchecked(i));
-                ));
-            }
-        }
-    }
-
-    if app.args.cores == 1 {
         stmts.push(quote!(
-            // To set the variable in cortex_m so the peripherals cannot be taken multiple times
-            let mut core: rtic::export::Peripherals = rtic::export::Peripherals::steal().into();
-        ));
-    } else {
-        stmts.push(quote!(
-            // NOTE(transmute) to avoid debug_assertion in multi-core mode
-            // (This code will go away when we drop multi-core mode)
-            let mut core: rtic::export::Peripherals = core::mem::transmute(());
+            (0..#cap).for_each(|i| #fq_ident.enqueue_unchecked(i));
         ));
     }
 
+    stmts.push(quote!(
+        // To set the variable in cortex_m so the peripherals cannot be taken multiple times
+        let mut core: rtic::export::Peripherals = rtic::export::Peripherals::steal().into();
+    ));
+
     let device = extra.device;
     let nvic_prio_bits = quote!(#device::NVIC_PRIO_BITS);
 
     // unmask interrupts and set their priorities
     for (&priority, name) in analysis
         .interrupts
-        .get(&core)
         .iter()
-        .flat_map(|interrupts| *interrupts)
         .chain(app.hardware_tasks.values().flat_map(|task| {
             if !util::is_exception(&task.args.binds) {
                 Some((&task.args.priority, &task.args.binds))
@@ -73,7 +57,7 @@ pub fn codegen(
         stmts.push(quote!(let _ = [(); ((1 << #nvic_prio_bits) - #priority as usize)];));
 
         // NOTE this also checks that the interrupt exists in the `Interrupt` enumeration
-        let interrupt = util::interrupt_ident(core, app.args.cores);
+        let interrupt = util::interrupt_ident();
         stmts.push(quote!(
             core.NVIC.set_priority(
                 #device::#interrupt::#name,
@@ -88,6 +72,7 @@ pub fn codegen(
 
     // cross-spawn barriers: now that priorities have been set and the interrupts have been unmasked
     // we are ready to receive messages from *other* cores
+    /*
     if analysis.spawn_barriers.contains_key(&core) {
         let sb = util::spawn_barrier(core);
         let shared = if cfg!(feature = "heterogeneous") {
@@ -108,6 +93,7 @@ pub fn codegen(
             #sb.release();
         ));
     }
+    */
 
     // set exception priorities
     for (name, priority) in app.hardware_tasks.values().filter_map(|task| {
@@ -126,8 +112,8 @@ pub fn codegen(
         );));
     }
 
-    // initialize the SysTick
-    if let Some(tq) = analysis.timer_queues.get(&core) {
+    // initialize the SysTick if there exist a TimerQueue
+    if let Some(tq) = analysis.timer_queues.first() {
         let priority = tq.priority;
 
         // compile time assert that this priority is supported by the device
@@ -146,11 +132,12 @@ pub fn codegen(
     }
 
     // if there's no user `#[idle]` then optimize returning from interrupt handlers
-    if app.idles.get(&core).is_none() {
+    if app.idles.is_empty() {
         // Set SLEEPONEXIT bit to enter sleep mode when returning from ISR
         stmts.push(quote!(core.SCB.scr.modify(|r| r | 1 << 1);));
     }
 
+    /*
     // cross-spawn barriers: wait until other cores are ready to receive messages
     for (&receiver, senders) in &analysis.spawn_barriers {
         // only block here if `init` can send messages to `receiver`
@@ -162,6 +149,7 @@ pub fn codegen(
             ));
         }
     }
+    */
 
-    (const_app, stmts)
+    stmts
 }
diff --git a/macros/src/codegen/resources.rs b/macros/src/codegen/resources.rs
index 0bec3e5a..07e01cb1 100644
--- a/macros/src/codegen/resources.rs
+++ b/macros/src/codegen/resources.rs
@@ -1,7 +1,7 @@
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 use rtic_syntax::{
-    analyze::{Location, Ownership},
+    analyze::Ownership,
     ast::App,
 };
 
@@ -21,38 +21,29 @@ pub fn codegen(
     let mut const_app = vec![];
     let mut mod_resources = vec![];
 
-    for (name, res, expr, loc) in app.resources(analysis) {
+    for (name, res, expr, _) in app.resources(analysis) {
         let cfgs = &res.cfgs;
         let ty = &res.ty;
 
         {
-            let (loc_attr, section) = match loc {
-                Location::Owned {
-                    core,
-                    cross_initialized: false,
-                } => (
-                    util::cfg_core(*core, app.args.cores),
-                    if expr.is_none() {
-                        util::link_section_uninit(Some(*core))
-                    } else {
-                        util::link_section("data", *core)
-                    },
-                ),
-
-                // shared `static`s and cross-initialized resources need to be in `.shared` memory
-                _ => (
-                    if cfg!(feature = "heterogeneous") {
-                        Some(quote!(#[rtic::export::shared]))
+            //let loc_attr = None;
+            let section = if expr.is_none() {
+                        util::link_section_uninit(true)
                     } else {
                         None
-                    },
+                    };
+            /*
+            let (loc_attr, section) = match loc {
+                Location::Owned => (
+                    None,
                     if expr.is_none() {
-                        util::link_section_uninit(None)
+                        util::link_section_uninit(true)
                     } else {
                         None
                     },
                 ),
             };
+            */
 
             let (ty, expr) = if let Some(expr) = expr {
                 (quote!(#ty), quote!(#expr))
@@ -68,25 +59,22 @@ pub fn codegen(
                 #[allow(non_upper_case_globals)]
                 #(#attrs)*
                 #(#cfgs)*
-                #loc_attr
+                //#loc_attr
                 #section
                 static mut #name: #ty = #expr;
             ));
         }
 
         if let Some(Ownership::Contended { ceiling }) = analysis.ownerships.get(name) {
-            let cfg_core = util::cfg_core(loc.core().expect("UNREACHABLE"), app.args.cores);
 
             mod_resources.push(quote!(
                 #[allow(non_camel_case_types)]
                 #(#cfgs)*
-                #cfg_core
                 pub struct #name<'a> {
                     priority: &'a Priority,
                 }
 
                 #(#cfgs)*
-                #cfg_core
                 impl<'a> #name<'a> {
                     #[inline(always)]
                     pub unsafe fn new(priority: &'a Priority) -> Self {
@@ -115,7 +103,6 @@ pub fn codegen(
             const_app.push(util::impl_mutex(
                 extra,
                 cfgs,
-                cfg_core.as_ref(),
                 true,
                 name,
                 quote!(#ty),
diff --git a/macros/src/codegen/resources_struct.rs b/macros/src/codegen/resources_struct.rs
index 994e751c..bd92a599 100644
--- a/macros/src/codegen/resources_struct.rs
+++ b/macros/src/codegen/resources_struct.rs
@@ -14,8 +14,8 @@ pub fn codegen(
     let mut lt = None;
 
     let resources = match ctxt {
-        Context::Init(core) => &app.inits[&core].args.resources,
-        Context::Idle(core) => &app.idles[&core].args.resources,
+        Context::Init => &app.inits[0].args.resources,
+        Context::Idle => &app.idles[0].args.resources,
         Context::HardwareTask(name) => &app.hardware_tasks[name].args.resources,
         Context::SoftwareTask(name) => &app.software_tasks[name].args.resources,
     };
@@ -147,13 +147,9 @@ pub fn codegen(
         }
     }
 
-    let core = ctxt.core(app);
-    let cores = app.args.cores;
-    let cfg_core = util::cfg_core(core, cores);
     let doc = format!("Resources `{}` has access to", ctxt.ident(app));
     let ident = util::resources_ident(ctxt, app);
     let item = quote!(
-        #cfg_core
         #[allow(non_snake_case)]
         #[doc = #doc]
         pub struct #ident<#lt> {
@@ -167,7 +163,6 @@ pub fn codegen(
         Some(quote!(priority: &#lt rtic::export::Priority))
     };
     let constructor = quote!(
-        #cfg_core
         impl<#lt> #ident<#lt> {
             #[inline(always)]
             unsafe fn new(#arg) -> Self {
diff --git a/macros/src/codegen/schedule.rs b/macros/src/codegen/schedule.rs
index 728d3a09..b6cb6b9a 100644
--- a/macros/src/codegen/schedule.rs
+++ b/macros/src/codegen/schedule.rs
@@ -1,4 +1,4 @@
-use std::collections::{BTreeMap, HashSet};
+use std::collections::HashSet;
 
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
@@ -13,14 +13,11 @@ use crate::{
 pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
     let mut items = vec![];
 
-    let mut seen = BTreeMap::<u8, HashSet<_>>::new();
+    let mut seen = HashSet::<_>::new();
     for (scheduler, schedulees) in app.schedule_callers() {
         let m = extra.monotonic();
         let instant = quote!(<#m as rtic::Monotonic>::Instant);
 
-        let sender = scheduler.core(app);
-        let cfg_sender = util::cfg_core(sender, app.args.cores);
-        let seen = seen.entry(sender).or_default();
         let mut methods = vec![];
 
         for name in schedulees {
@@ -35,7 +32,7 @@ pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
 
                 let body = schedule_body::codegen(scheduler, &name, app);
 
-                let section = util::link_section("text", sender);
+                let section = util::link_section("text");
                 methods.push(quote!(
                     #(#cfgs)*
                     #section
@@ -44,7 +41,7 @@ pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
                     }
                 ));
             } else {
-                let schedule = util::schedule_ident(name, sender);
+                let schedule = util::schedule_ident(name);
 
                 if !seen.contains(name) {
                     // generate a `schedule_${name}_S${sender}` function
@@ -52,9 +49,8 @@ pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
 
                     let body = schedule_body::codegen(scheduler, &name, app);
 
-                    let section = util::link_section("text", sender);
+                    let section = util::link_section("text");
                     items.push(quote!(
-                        #cfg_sender
                         #(#cfgs)*
                         #section
                         unsafe fn #schedule(
@@ -88,7 +84,6 @@ pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
         let scheduler = scheduler.ident(app);
         debug_assert!(!methods.is_empty());
         items.push(quote!(
-            #cfg_sender
             impl<#lt> #scheduler::Schedule<#lt> {
                 #(#methods)*
             }
diff --git a/macros/src/codegen/schedule_body.rs b/macros/src/codegen/schedule_body.rs
index 8fd026c2..644930d7 100644
--- a/macros/src/codegen/schedule_body.rs
+++ b/macros/src/codegen/schedule_body.rs
@@ -6,12 +6,10 @@ use syn::Ident;
 use crate::codegen::util;
 
 pub fn codegen(scheduler: Context, name: &Ident, app: &App) -> TokenStream2 {
-    let sender = scheduler.core(app);
     let schedulee = &app.software_tasks[name];
-    let receiver = schedulee.args.core;
 
-    let fq = util::fq_ident(name, sender);
-    let tq = util::tq_ident(sender);
+    let fq = util::fq_ident(name);
+    let tq = util::tq_ident();
     let (dequeue, enqueue) = if scheduler.is_init() {
         (quote!(#fq.dequeue()), quote!(#tq.enqueue_unchecked(nr);))
     } else {
@@ -21,8 +19,8 @@ pub fn codegen(scheduler: Context, name: &Ident, app: &App) -> TokenStream2 {
         )
     };
 
-    let write_instant = if app.uses_schedule(receiver) {
-        let instants = util::instants_ident(name, sender);
+    let write_instant = if app.uses_schedule() {
+        let instants = util::instants_ident(name);
 
         Some(quote!(
             #instants.get_unchecked_mut(usize::from(index)).as_mut_ptr().write(instant);
@@ -32,8 +30,8 @@ pub fn codegen(scheduler: Context, name: &Ident, app: &App) -> TokenStream2 {
     };
 
     let (_, tupled, _, _) = util::regroup_inputs(&schedulee.inputs);
-    let inputs = util::inputs_ident(name, sender);
-    let t = util::schedule_t_ident(sender);
+    let inputs = util::inputs_ident(name);
+    let t = util::schedule_t_ident();
     quote!(
         unsafe {
             use rtic::Mutex as _;
diff --git a/macros/src/codegen/software_tasks.rs b/macros/src/codegen/software_tasks.rs
index 14a57633..25662801 100644
--- a/macros/src/codegen/software_tasks.rs
+++ b/macros/src/codegen/software_tasks.rs
@@ -28,8 +28,6 @@ pub fn codegen(
     let mut user_tasks = vec![];
 
     for (name, task) in &app.software_tasks {
-        let receiver = task.args.core;
-
         let inputs = &task.inputs;
         let (_, _, _, input_ty) = util::regroup_inputs(inputs);
 
@@ -38,102 +36,73 @@ pub fn codegen(
         let cap_ty = util::capacity_typenum(cap, true);
 
         // create free queues and inputs / instants buffers
-        if let Some(free_queues) = analysis.free_queues.get(name) {
-            for (&sender, &ceiling) in free_queues {
-                let cfg_sender = util::cfg_core(sender, app.args.cores);
-                let fq = util::fq_ident(name, sender);
-
-                let (loc, fq_ty, fq_expr, bss, mk_uninit): (
-                    _,
-                    _,
-                    _,
-                    _,
-                    Box<dyn Fn() -> Option<_>>,
-                ) = if receiver == sender {
-                    (
-                        cfg_sender.clone(),
-                        quote!(rtic::export::SCFQ<#cap_ty>),
-                        quote!(rtic::export::Queue(unsafe {
-                            rtic::export::iQueue::u8_sc()
-                        })),
-                        util::link_section("bss", sender),
-                        Box::new(|| util::link_section_uninit(Some(sender))),
-                    )
-                } else {
-                    let shared = if cfg!(feature = "heterogeneous") {
-                        Some(quote!(#[rtic::export::shared]))
-                    } else {
-                        None
-                    };
-
-                    (
-                        shared,
-                        quote!(rtic::export::MCFQ<#cap_ty>),
-                        quote!(rtic::export::Queue(rtic::export::iQueue::u8())),
-                        None,
-                        Box::new(|| util::link_section_uninit(None)),
-                    )
-                };
-                let loc = &loc;
-
+        //if let Some(free_queues) = analysis.free_queues.get(name) {
+        //for (&sender, &ceiling) in free_queues {
+        if let Some(&ceiling) = analysis.free_queues.get(name) {
+            let fq = util::fq_ident(name);
+
+            let (fq_ty, fq_expr, bss, mk_uninit): (_, _, _, Box<dyn Fn() -> Option<_>>) = {
+                (
+                    quote!(rtic::export::SCFQ<#cap_ty>),
+                    quote!(rtic::export::Queue(unsafe {
+                        rtic::export::iQueue::u8_sc()
+                    })),
+                    util::link_section("bss"),
+                    Box::new(|| util::link_section_uninit(true)),
+                )
+            };
+            const_app.push(quote!(
+                /// Queue version of a free-list that keeps track of empty slots in
+                /// the following buffers
+                #bss
+                static mut #fq: #fq_ty = #fq_expr;
+            ));
+
+            // Generate a resource proxy if needed
+            if let Some(ceiling) = ceiling {
                 const_app.push(quote!(
-                    /// Queue version of a free-list that keeps track of empty slots in
-                    /// the following buffers
-                    #loc
-                    #bss
-                    static mut #fq: #fq_ty = #fq_expr;
+                    struct #fq<'a> {
+                        priority: &'a rtic::export::Priority,
+                    }
                 ));
 
-                // Generate a resource proxy if needed
-                if let Some(ceiling) = ceiling {
-                    const_app.push(quote!(
-                        #cfg_sender
-                        struct #fq<'a> {
-                            priority: &'a rtic::export::Priority,
-                        }
-                    ));
-
-                    const_app.push(util::impl_mutex(
-                        extra,
-                        &[],
-                        cfg_sender.as_ref(),
-                        false,
-                        &fq,
-                        fq_ty,
-                        ceiling,
-                        quote!(&mut #fq),
-                    ));
-                }
-
-                let ref elems = (0..cap)
-                    .map(|_| quote!(core::mem::MaybeUninit::uninit()))
-                    .collect::<Vec<_>>();
-
-                if app.uses_schedule(receiver) {
-                    let m = extra.monotonic();
-                    let instants = util::instants_ident(name, sender);
-
-                    let uninit = mk_uninit();
-                    const_app.push(quote!(
-                        #loc
-                        #uninit
-                        /// Buffer that holds the instants associated to the inputs of a task
-                        static mut #instants:
-                            [core::mem::MaybeUninit<<#m as rtic::Monotonic>::Instant>; #cap_lit] =
-                            [#(#elems,)*];
-                    ));
-                }
+                const_app.push(util::impl_mutex(
+                    extra,
+                    &[],
+                    false,
+                    &fq,
+                    fq_ty,
+                    ceiling,
+                    quote!(&mut #fq),
+                ));
+            }
+
+            let ref elems = (0..cap)
+                .map(|_| quote!(core::mem::MaybeUninit::uninit()))
+                .collect::<Vec<_>>();
+
+            if app.uses_schedule() {
+                let m = extra.monotonic();
+                let instants = util::instants_ident(name);
 
                 let uninit = mk_uninit();
-                let inputs = util::inputs_ident(name, sender);
                 const_app.push(quote!(
-                    #loc
                     #uninit
-                    /// Buffer that holds the inputs of a task
-                    static mut #inputs: [core::mem::MaybeUninit<#input_ty>; #cap_lit] =
+                    /// Buffer that holds the instants associated to the inputs of a task
+                    static mut #instants:
+                        [core::mem::MaybeUninit<<#m as rtic::Monotonic>::Instant>; #cap_lit] =
                         [#(#elems,)*];
                 ));
             }
+
+            let uninit = mk_uninit();
+            let inputs = util::inputs_ident(name);
+            const_app.push(quote!(
+                #uninit
+                /// Buffer that holds the inputs of a task
+                static mut #inputs: [core::mem::MaybeUninit<#input_ty>; #cap_lit] =
+                    [#(#elems,)*];
+            ));
         }
 
         // `${task}Resources`
@@ -155,15 +124,13 @@ pub fn codegen(
         // `${task}Locals`
         let mut locals_pat = None;
         if !task.locals.is_empty() {
-            let (struct_, pat) =
-                locals::codegen(Context::SoftwareTask(name), &task.locals, receiver, app);
+            let (struct_, pat) = locals::codegen(Context::SoftwareTask(name), &task.locals, app);
 
             locals_pat = Some(pat);
             root.push(struct_);
         }
 
-        let cfg_receiver = util::cfg_core(receiver, app.args.cores);
-        let section = util::link_section("text", receiver);
+        let section = util::link_section("text");
         let context = &task.context;
         let attrs = &task.attrs;
         let cfgs = &task.cfgs;
@@ -173,7 +140,6 @@ pub fn codegen(
             #(#attrs)*
             #(#cfgs)*
             #[allow(non_snake_case)]
-            #cfg_receiver
             #section
             fn #name(#(#locals_pat,)* #context: #name::Context #(,#inputs)*) {
                 use rtic::Mutex as _;
diff --git a/macros/src/codegen/spawn.rs b/macros/src/codegen/spawn.rs
index 287c92a1..6cad809b 100644
--- a/macros/src/codegen/spawn.rs
+++ b/macros/src/codegen/spawn.rs
@@ -1,4 +1,4 @@
-use std::collections::{BTreeMap, HashSet};
+use std::collections::HashSet;
 
 use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
@@ -14,16 +14,13 @@ use crate::{
 pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream2> {
     let mut items = vec![];
 
-    let mut seen = BTreeMap::<u8, HashSet<_>>::new();
+    let mut seen = HashSet::<_>::new();
     for (spawner, spawnees) in app.spawn_callers() {
-        let sender = spawner.core(app);
-        let cfg_sender = util::cfg_core(sender, app.args.cores);
-        let seen = seen.entry(sender).or_default();
         let mut methods = vec![];
 
         for name in spawnees {
             let spawnee = &app.software_tasks[name];
-            let receiver = spawnee.args.core;
+            //let receiver = spawnee.args.core;
             let cfgs = &spawnee.cfgs;
             let (args, _, untupled, ty) = util::regroup_inputs(&spawnee.inputs);
             let args = &args;
@@ -34,7 +31,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
 
                 let body = spawn_body::codegen(spawner, &name, app, analysis, extra);
 
-                let let_instant = if app.uses_schedule(receiver) {
+                let let_instant = if app.uses_schedule() {
                     let m = extra.monotonic();
 
                     Some(quote!(let instant = unsafe { <#m as rtic::Monotonic>::zero() };))
@@ -42,7 +39,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                     None
                 };
 
-                let section = util::link_section("text", sender);
+                let section = util::link_section("text");
                 methods.push(quote!(
                     #(#cfgs)*
                     #section
@@ -52,13 +49,13 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                     }
                 ));
             } else {
-                let spawn = util::spawn_ident(name, sender);
+                let spawn = util::spawn_ident(name);
 
                 if !seen.contains(name) {
                     // generate a `spawn_${name}_S${sender}` function
                     seen.insert(name);
 
-                    let instant = if app.uses_schedule(receiver) {
+                    let instant = if app.uses_schedule() {
                         let m = extra.monotonic();
 
                         Some(quote!(, instant: <#m as rtic::Monotonic>::Instant))
@@ -68,9 +65,9 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
 
                     let body = spawn_body::codegen(spawner, &name, app, analysis, extra);
 
-                    let section = util::link_section("text", sender);
+                    let section = util::link_section("text");
                     items.push(quote!(
-                        #cfg_sender
+                        //#cfg_sender
                         #(#cfgs)*
                         #section
                         unsafe fn #spawn(
@@ -83,7 +80,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                     ));
                 }
 
-                let (let_instant, instant) = if app.uses_schedule(receiver) {
+                let (let_instant, instant) = if app.uses_schedule() {
                     let m = extra.monotonic();
 
                     (
@@ -120,7 +117,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
         let spawner = spawner.ident(app);
         debug_assert!(!methods.is_empty());
         items.push(quote!(
-            #cfg_sender
+            //#cfg_sender
             impl<#lt> #spawner::Spawn<#lt> {
                 #(#methods)*
             }
diff --git a/macros/src/codegen/spawn_body.rs b/macros/src/codegen/spawn_body.rs
index 3433875e..3c2e8a03 100644
--- a/macros/src/codegen/spawn_body.rs
+++ b/macros/src/codegen/spawn_body.rs
@@ -12,13 +12,11 @@ pub fn codegen(
     analysis: &Analysis,
     extra: &Extra,
 ) -> TokenStream2 {
-    let sender = spawner.core(app);
     let spawnee = &app.software_tasks[name];
     let priority = spawnee.args.priority;
-    let receiver = spawnee.args.core;
 
-    let write_instant = if app.uses_schedule(receiver) {
-        let instants = util::instants_ident(name, sender);
+    let write_instant = if app.uses_schedule() {
+        let instants = util::instants_ident(name);
 
         Some(quote!(
             #instants.get_unchecked_mut(usize::from(index)).as_mut_ptr().write(instant);
@@ -27,9 +25,9 @@ pub fn codegen(
         None
     };
 
-    let t = util::spawn_t_ident(receiver, priority, sender);
-    let fq = util::fq_ident(name, sender);
-    let rq = util::rq_ident(receiver, priority, sender);
+    let t = util::spawn_t_ident(priority);
+    let fq = util::fq_ident(name);
+    let rq = util::rq_ident(priority);
     let (dequeue, enqueue) = if spawner.is_init() {
         (
             quote!(#fq.dequeue()),
@@ -45,20 +43,15 @@ pub fn codegen(
     };
 
     let device = extra.device;
-    let enum_ = util::interrupt_ident(receiver, app.args.cores);
-    let interrupt = &analysis.interrupts[&receiver][&priority];
-    let pend = if sender != receiver {
-        quote!(
-            #device::xpend(#receiver, #device::#enum_::#interrupt);
-        )
-    } else {
-        quote!(
+    let enum_ = util::interrupt_ident();
+    let interrupt = &analysis.interrupts.get(&priority);
+    let pend = {quote!(
             rtic::pend(#device::#enum_::#interrupt);
         )
     };
 
     let (_, tupled, _, _) = util::regroup_inputs(&spawnee.inputs);
-    let inputs = util::inputs_ident(name, sender);
+    let inputs = util::inputs_ident(name);
     quote!(
         unsafe {
             use rtic::Mutex as _;
diff --git a/macros/src/codegen/timer_queue.rs b/macros/src/codegen/timer_queue.rs
index 56304001..41f5520e 100644
--- a/macros/src/codegen/timer_queue.rs
+++ b/macros/src/codegen/timer_queue.rs
@@ -8,9 +8,9 @@ use crate::{analyze::Analysis, check::Extra, codegen::util};
 pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream2> {
     let mut items = vec![];
 
-    for (&sender, timer_queue) in &analysis.timer_queues {
-        let cfg_sender = util::cfg_core(sender, app.args.cores);
-        let t = util::schedule_t_ident(sender);
+    if let Some(timer_queue) = &analysis.timer_queues.first() {
+        //let cfg_sender = util::cfg_core(sender, app.args.cores);
+        let t = util::schedule_t_ident();
 
         // Enumeration of `schedule`-able tasks
         {
@@ -27,9 +27,9 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                 })
                 .collect::<Vec<_>>();
 
-            let doc = format!("Tasks that can be scheduled from core #{}", sender);
+            let doc = format!("Tasks that can be scheduled");
             items.push(quote!(
-                #cfg_sender
+                //#cfg_sender
                 #[doc = #doc]
                 #[allow(non_camel_case_types)]
                 #[derive(Clone, Copy)]
@@ -39,18 +39,18 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
             ));
         }
 
-        let tq = util::tq_ident(sender);
+        let tq = util::tq_ident();
 
         // Static variable and resource proxy
         {
-            let doc = format!("Core #{} timer queue", sender);
+            let doc = format!("Timer queue");
             let m = extra.monotonic();
             let n = util::capacity_typenum(timer_queue.capacity, false);
             let tq_ty = quote!(rtic::export::TimerQueue<#m, #t, #n>);
 
-            let section = util::link_section("bss", sender);
+            let section = util::link_section("bss");
             items.push(quote!(
-                #cfg_sender
+                //#cfg_sender
                 #[doc = #doc]
                 #section
                 static mut #tq: #tq_ty = rtic::export::TimerQueue(
@@ -59,7 +59,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                     )
                 );
 
-                #cfg_sender
+                //#cfg_sender
                 struct #tq<'a> {
                     priority: &'a rtic::export::Priority,
                 }
@@ -68,7 +68,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
             items.push(util::impl_mutex(
                 extra,
                 &[],
-                cfg_sender.as_ref(),
+                //cfg_sender.as_ref(),
                 false,
                 &tq,
                 tq_ty,
@@ -88,17 +88,12 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
 
                     let cfgs = &task.cfgs;
                     let priority = task.args.priority;
-                    let receiver = task.args.core;
-                    let rq = util::rq_ident(receiver, priority, sender);
-                    let rqt = util::spawn_t_ident(receiver, priority, sender);
-                    let enum_ = util::interrupt_ident(receiver, app.args.cores);
-                    let interrupt = &analysis.interrupts[&receiver][&priority];
+                    let rq = util::rq_ident(priority);
+                    let rqt = util::spawn_t_ident(priority);
+                    let enum_ = util::interrupt_ident();
+                    let interrupt = &analysis.interrupts.get(&priority);
 
-                    let pend = if sender != receiver {
-                        quote!(
-                            #device::xpend(#receiver, #device::#enum_::#interrupt);
-                        )
-                    } else {
+                    let pend = {
                         quote!(
                             rtic::pend(#device::#enum_::#interrupt);
                         )
@@ -118,11 +113,11 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                 .collect::<Vec<_>>();
 
             let priority = timer_queue.priority;
-            let sys_tick = util::suffixed("SysTick", sender);
-            let section = util::link_section("text", sender);
+            let sys_tick = util::suffixed("SysTick");
+            let section = util::link_section("text");
             items.push(quote!(
                 #[no_mangle]
-                #cfg_sender
+                //#cfg_sender
                 #section
                 unsafe fn #sys_tick() {
                     use rtic::Mutex as _;
@@ -137,7 +132,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                         })
                         // NOTE `inline(always)` produces faster and smaller code
                             .lock(#[inline(always)]
-                                  |tq| tq.dequeue())
+                                |tq| tq.dequeue())
                         {
                             match task {
                                 #(#arms)*
@@ -148,6 +143,5 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
             ));
         }
     }
-
     items
 }
diff --git a/macros/src/codegen/util.rs b/macros/src/codegen/util.rs
index 68aca5d1..c375e4eb 100644
--- a/macros/src/codegen/util.rs
+++ b/macros/src/codegen/util.rs
@@ -2,7 +2,7 @@ use core::sync::atomic::{AtomicUsize, Ordering};
 
 use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::quote;
-use rtic_syntax::{ast::App, Context, Core};
+use rtic_syntax::{ast::App, Context};
 use syn::{Attribute, Ident, LitInt, PatType};
 
 use crate::check::Extra;
@@ -25,6 +25,7 @@ pub fn capacity_typenum(capacity: u8, round_up_to_power_of_two: bool) -> TokenSt
     quote!(rtic::export::consts::#ident)
 }
 
+/*
 /// Generates a `#[cfg(core = "0")]` attribute if we are in multi-core mode
 pub fn cfg_core(core: Core, cores: u8) -> Option<TokenStream2> {
     if cores == 1 {
@@ -36,14 +37,15 @@ pub fn cfg_core(core: Core, cores: u8) -> Option<TokenStream2> {
         None
     }
 }
+*/
 
 /// Identifier for the free queue
 ///
 /// There may be more than one free queue per task because we need one for each sender core so we
 /// include the sender (e.g. `S0`) in the name
-pub fn fq_ident(task: &Ident, sender: Core) -> Ident {
+pub fn fq_ident(task: &Ident) -> Ident {
     Ident::new(
-        &format!("{}_S{}_FQ", task.to_string(), sender),
+        &format!("{}_FQ", task.to_string()),
         Span::call_site(),
     )
 }
@@ -52,7 +54,7 @@ pub fn fq_ident(task: &Ident, sender: Core) -> Ident {
 pub fn impl_mutex(
     extra: &Extra,
     cfgs: &[Attribute],
-    cfg_core: Option<&TokenStream2>,
+    //cfg_core: Option<&TokenStream2>,
     resources_prefix: bool,
     name: &Ident,
     ty: TokenStream2,
@@ -68,7 +70,7 @@ pub fn impl_mutex(
     let device = extra.device;
     quote!(
         #(#cfgs)*
-        #cfg_core
+        //#cfg_core
         impl<'a> rtic::Mutex for #path<'a> {
             type T = #ty;
 
@@ -91,28 +93,26 @@ pub fn impl_mutex(
     )
 }
 
+/*
 /// Generates an identifier for a cross-initialization barrier
 pub fn init_barrier(initializer: Core) -> Ident {
     Ident::new(&format!("IB{}", initializer), Span::call_site())
 }
+*/
 
 /// Generates an identifier for the `INPUTS` buffer (`spawn` & `schedule` API)
-pub fn inputs_ident(task: &Ident, sender: Core) -> Ident {
-    Ident::new(&format!("{}_S{}_INPUTS", task, sender), Span::call_site())
+pub fn inputs_ident(task: &Ident) -> Ident {
+    Ident::new(&format!("{}_INPUTS", task), Span::call_site())
 }
 
 /// Generates an identifier for the `INSTANTS` buffer (`schedule` API)
-pub fn instants_ident(task: &Ident, sender: Core) -> Ident {
-    Ident::new(&format!("{}_S{}_INSTANTS", task, sender), Span::call_site())
+pub fn instants_ident(task: &Ident) -> Ident {
+    Ident::new(&format!("{}_INSTANTS", task), Span::call_site())
 }
 
-pub fn interrupt_ident(core: Core, cores: u8) -> Ident {
+pub fn interrupt_ident() -> Ident {
     let span = Span::call_site();
-    if cores == 1 {
         Ident::new("Interrupt", span)
-    } else {
-        Ident::new(&format!("Interrupt_{}", core), span)
-    }
 }
 
 /// Whether `name` is an exception with configurable priority
@@ -141,31 +141,24 @@ fn link_section_index() -> usize {
     INDEX.fetch_add(1, Ordering::Relaxed)
 }
 
-pub fn link_section(section: &str, core: Core) -> Option<TokenStream2> {
+pub fn link_section(_section: &str) -> Option<TokenStream2> {
+    /*
     if cfg!(feature = "homogeneous") {
         let section = format!(".{}_{}.rtic{}", section, core, link_section_index());
         Some(quote!(#[link_section = #section]))
     } else {
         None
     }
+    */
+    None
 }
 
 // NOTE `None` means in shared memory
-pub fn link_section_uninit(core: Option<Core>) -> Option<TokenStream2> {
-    let section = if let Some(core) = core {
+pub fn link_section_uninit(empty_expr: bool) -> Option<TokenStream2> {
+    let section = if empty_expr {
         let index = link_section_index();
-
-        if cfg!(feature = "homogeneous") {
-            format!(".uninit_{}.rtic{}", core, index)
-        } else {
-            format!(".uninit.rtic{}", index)
-        }
+        format!(".uninit.rtic{}", index)
     } else {
-        if cfg!(feature = "heterogeneous") {
-            // `#[shared]` attribute sets the linker section
-            return None;
-        }
-
         format!(".uninit.rtic{}", link_section_index())
     };
 
@@ -175,8 +168,8 @@ pub fn link_section_uninit(core: Option<Core>) -> Option<TokenStream2> {
 /// Generates a pre-reexport identifier for the "locals" struct
 pub fn locals_ident(ctxt: Context, app: &App) -> Ident {
     let mut s = match ctxt {
-        Context::Init(core) => app.inits[&core].name.to_string(),
-        Context::Idle(core) => app.idles[&core].name.to_string(),
+        Context::Init => app.inits[0].name.to_string(),
+        Context::Idle => app.idles[0].name.to_string(),
         Context::HardwareTask(ident) | Context::SoftwareTask(ident) => ident.to_string(),
     };
 
@@ -185,10 +178,12 @@ pub fn locals_ident(ctxt: Context, app: &App) -> Ident {
     Ident::new(&s, Span::call_site())
 }
 
+/*
 /// Generates an identifier for a rendezvous barrier
-pub fn rendezvous_ident(core: Core) -> Ident {
-    Ident::new(&format!("RV{}", core), Span::call_site())
+pub fn rendezvous_ident() -> Ident {
+    Ident::new(&format!("RV"), Span::call_site())
 }
+*/
 
 // Regroups the inputs of a task
 //
@@ -242,8 +237,8 @@ pub fn regroup_inputs(
 /// Generates a pre-reexport identifier for the "resources" struct
 pub fn resources_ident(ctxt: Context, app: &App) -> Ident {
     let mut s = match ctxt {
-        Context::Init(core) => app.inits[&core].name.to_string(),
-        Context::Idle(core) => app.idles[&core].name.to_string(),
+        Context::Init => app.inits[0].name.to_string(),
+        Context::Idle => app.idles[0].name.to_string(),
         Context::HardwareTask(ident) | Context::SoftwareTask(ident) => ident.to_string(),
     };
 
@@ -257,9 +252,9 @@ pub fn resources_ident(ctxt: Context, app: &App) -> Ident {
 /// Each core may have several task dispatchers, one for each priority level. Each task dispatcher
 /// in turn may use more than one ready queue because the queues are SPSC queues so one is needed
 /// per sender core.
-pub fn rq_ident(receiver: Core, priority: u8, sender: Core) -> Ident {
+pub fn rq_ident(priority: u8) -> Ident {
     Ident::new(
-        &format!("R{}_P{}_S{}_RQ", receiver, priority, sender),
+        &format!("P{}_RQ", priority),
         Span::call_site(),
     )
 }
@@ -268,30 +263,32 @@ pub fn rq_ident(receiver: Core, priority: u8, sender: Core) -> Ident {
 ///
 /// The methods of the `Schedule` structs invoke these functions. As one task may be `schedule`-ed
 /// by different cores we need one "schedule" function per possible task-sender pair
-pub fn schedule_ident(name: &Ident, sender: Core) -> Ident {
+pub fn schedule_ident(name: &Ident) -> Ident {
     Ident::new(
-        &format!("schedule_{}_S{}", name.to_string(), sender),
+        &format!("schedule_{}", name.to_string()),
         Span::call_site(),
     )
 }
 
 /// Generates an identifier for the `enum` of `schedule`-able tasks
-pub fn schedule_t_ident(core: Core) -> Ident {
-    Ident::new(&format!("T{}", core), Span::call_site())
+pub fn schedule_t_ident() -> Ident {
+    Ident::new(&format!("T"), Span::call_site())
 }
 
+/*
 /// Generates an identifier for a cross-spawn barrier
-pub fn spawn_barrier(receiver: Core) -> Ident {
-    Ident::new(&format!("SB{}", receiver), Span::call_site())
+pub fn spawn_barrier() -> Ident {
+    Ident::new(&format!("SB"), Span::call_site())
 }
+*/
 
 /// Generates an identifier for a "spawn" function
 ///
 /// The methods of the `Spawn` structs invoke these functions. As one task may be `spawn`-ed by
 /// different cores we need one "spawn" function per possible task-sender pair
-pub fn spawn_ident(name: &Ident, sender: Core) -> Ident {
+pub fn spawn_ident(name: &Ident) -> Ident {
     Ident::new(
-        &format!("spawn_{}_S{}", name.to_string(), sender),
+        &format!("spawn_{}", name.to_string()),
         Span::call_site(),
     )
 }
@@ -300,26 +297,21 @@ pub fn spawn_ident(name: &Ident, sender: Core) -> Ident {
 ///
 /// This identifier needs the same structure as the `RQ` identifier because there's one ready queue
 /// for each of these `T` enums
-pub fn spawn_t_ident(receiver: Core, priority: u8, sender: Core) -> Ident {
+pub fn spawn_t_ident(priority: u8) -> Ident {
     Ident::new(
-        &format!("R{}_P{}_S{}_T", receiver, priority, sender),
+        &format!("P{}_T", priority),
         Span::call_site(),
     )
 }
 
-pub fn suffixed(name: &str, core: u8) -> Ident {
+pub fn suffixed(name: &str) -> Ident {
     let span = Span::call_site();
-
-    if cfg!(feature = "homogeneous") {
-        Ident::new(&format!("{}_{}", name, core), span)
-    } else {
-        Ident::new(name, span)
-    }
+    Ident::new(name, span)
 }
 
 /// Generates an identifier for a timer queue
 ///
 /// At most there's one timer queue per core
-pub fn tq_ident(core: Core) -> Ident {
-    Ident::new(&format!("TQ{}", core), Span::call_site())
+pub fn tq_ident() -> Ident {
+    Ident::new(&format!("TQ"), Span::call_site())
 }
diff --git a/macros/src/lib.rs b/macros/src/lib.rs
index b5803628..7b72c7fb 100644
--- a/macros/src/lib.rs
+++ b/macros/src/lib.rs
@@ -201,12 +201,12 @@ mod tests;
 ///
 /// Attributes can be applied to the functions inside this block. These attributes will be forwarded
 /// to the interrupt handlers generated by the `app` attribute.
+
 #[proc_macro_attribute]
 pub fn app(args: TokenStream, input: TokenStream) -> TokenStream {
     let mut settings = Settings::default();
     settings.optimize_priorities = true;
     settings.parse_binds = true;
-    settings.parse_cores = cfg!(feature = "heterogeneous") || cfg!(feature = "homogeneous");
     settings.parse_extern_interrupt = true;
     settings.parse_schedule = true;
 
diff --git a/macros/src/tests.rs b/macros/src/tests.rs
index 94969d1a..e9e3326e 100644
--- a/macros/src/tests.rs
+++ b/macros/src/tests.rs
@@ -1,5 +1,4 @@
 // NOTE these tests are specific to the Cortex-M port; `rtic-syntax` has a more extensive test suite
 // that tests functionality common to all the RTIC ports
 
-mod multi;
 mod single;
diff --git a/macros/src/tests/multi.rs b/macros/src/tests/multi.rs
deleted file mode 100644
index 366789be..00000000
--- a/macros/src/tests/multi.rs
+++ /dev/null
@@ -1,59 +0,0 @@
-use quote::quote;
-use rtic_syntax::Settings;
-
-#[test]
-fn analyze() {
-    let mut settings = Settings::default();
-    settings.parse_cores = true;
-    settings.parse_extern_interrupt = true;
-
-    let (app, analysis) = rtic_syntax::parse2(
-        quote!(device = pac, cores = 2),
-        quote!(
-            const APP: () = {
-                #[task(core = 0, priority = 1)]
-                fn a(_: a::Context) {}
-
-                #[task(core = 0, priority = 2)]
-                fn b(_: b::Context) {}
-
-                #[task(core = 1, priority = 1)]
-                fn c(_: c::Context) {}
-
-                #[task(core = 1, priority = 2)]
-                fn d(_: d::Context) {}
-
-                // first interrupt is assigned to the highest priority dispatcher
-                extern "C" {
-                    #[core = 0]
-                    fn B();
-
-                    #[core = 0]
-                    fn A();
-
-                    #[core = 1]
-                    fn A();
-
-                    #[core = 1]
-                    fn C();
-                }
-            };
-        ),
-        settings,
-    )
-    .unwrap();
-
-    let analysis = crate::analyze::app(analysis, &app);
-
-    // first core
-    let interrupts0 = &analysis.interrupts[&0];
-    assert_eq!(interrupts0.len(), 2);
-    assert_eq!(interrupts0[&2].to_string(), "B");
-    assert_eq!(interrupts0[&1].to_string(), "A");
-
-    // second core
-    let interrupts1 = &analysis.interrupts[&1];
-    assert_eq!(interrupts1.len(), 2);
-    assert_eq!(interrupts1[&2].to_string(), "A");
-    assert_eq!(interrupts1[&1].to_string(), "C");
-}
diff --git a/macros/src/tests/single.rs b/macros/src/tests/single.rs
index 497d1da7..6d4fb23a 100644
--- a/macros/src/tests/single.rs
+++ b/macros/src/tests/single.rs
@@ -27,7 +27,7 @@ fn analyze() {
     .unwrap();
 
     let analysis = crate::analyze::app(analysis, &app);
-    let interrupts = &analysis.interrupts[&0];
+    let interrupts = &analysis.interrupts;
     assert_eq!(interrupts.len(), 2);
     assert_eq!(interrupts[&2].to_string(), "B");
     assert_eq!(interrupts[&1].to_string(), "A");
diff --git a/src/export.rs b/src/export.rs
index e23b8f3a..8e5ef433 100644
--- a/src/export.rs
+++ b/src/export.rs
@@ -12,14 +12,12 @@ pub use cortex_m::{
     peripheral::{scb::SystemHandler, syst::SystClkSource, DWT, NVIC},
     Peripherals,
 };
-use heapless::spsc::{MultiCore, SingleCore};
+use heapless::spsc::SingleCore;
 pub use heapless::{consts, i::Queue as iQueue, spsc::Queue};
 pub use heapless::{i::BinaryHeap as iBinaryHeap, BinaryHeap};
 #[cfg(feature = "heterogeneous")]
 pub use microamp::shared;
 
-pub type MCFQ<N> = Queue<u8, N, u8, MultiCore>;
-pub type MCRQ<T, N> = Queue<(T, u8), N, u8, MultiCore>;
 pub type SCFQ<N> = Queue<u8, N, u8, SingleCore>;
 pub type SCRQ<T, N> = Queue<(T, u8), N, u8, SingleCore>;
 
@@ -108,13 +106,6 @@ where
 {
 }
 
-#[inline(always)]
-pub fn assert_multicore<T>()
-where
-    T: super::MultiCore,
-{
-}
-
 #[cfg(armv7m)]
 #[inline(always)]
 pub unsafe fn lock<T, R>(
diff --git a/src/lib.rs b/src/lib.rs
index 50036531..1c50f78f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -161,9 +161,6 @@ pub trait Monotonic {
     fn zero() -> Self::Instant;
 }
 
-/// A marker trait that indicates that it is correct to use this type in multi-core context
-pub trait MultiCore {}
-
 /// Sets the given `interrupt` as pending
 ///
 /// This is a convenience function around